March Lawn Care
As spring comes closer, gardeners are anxious to get outside. And for many of us, spring is the time to start working on our lawns. There are a few tasks to do in March but don’t get overly anxious, especially not with fertilizer. Spring is a perfect time to perform a soil test, including separate ones for your back and front lawn. This should be done about every 3 years — prior to adding any supplements for the season.
The Charlottesville-Albemarle Extension Office now offers a new program called Healthy Virginia Lawns. A trained Master Gardener will come to your site, measure your lawn and assist with collecting the soil test. When the results are received, they will contact you with a nutrient management plan. For further information, call 434-872-4580 or email firstname.lastname@example.org. In next month’s newsletter, there will be an in-depth article on soil testing, including how to collect the soil properly and how to interpret the results. If you are anxious to do it this month, consult Soil Sampling for the Home Gardener, Virginia Cooperative Extension publication at: http://pubs.ext.vt.edu/452-129/.
Spring is not the ideal time to establish cool-season grasses such as fescue because in spring, fescue has a minimal amount of time to develop an extensive root system before the heat of summer. However, there are circumstances that require spring planting, such as new construction or bare patches. Optimize your chances of success by selecting a seed variety that suits your situation, such as shade or sun. Plant when soil temperatures are 55°-65°F, and till to a four to six inch depth in compacted areas. For success, be sure to have good soil preparation and sufficient watering. For a complete discussion, go to http://pubs.ext.vt.edu/426-718/. Lawn reseeding will be discussed further in the fall newsletter because fall is the optimal time of the year for renovating your lawn.
Dr. Shawn Askew, Virginia Tech’s Extension Turfgrass Weed Specialist, says the absolute BEST weed control in the lawn IS the lawn. In other words, if we manage our lawn appropriately, the weeds will be reduced. Weeds are often an indication of problems in the grass environment. If we can determine the underlying problem, we may be more successful. For example, knotweed usually indicates compacted soil. Thus to solve the problem or at least reduce it, aeration of the lawn is needed.
Classification of Weeds
Lawn weeds can be divided into 2 classes — weedy grasses such as crabgrass and quackgrass, and broadleaf weeds such as dandelion, clover, knotweed and plantain. These two classes are further subdivided according to the length of their lives. Perennial weeds have a lifetime of over 2 years. Annual weeds germinate from seed, grow, flower, and produce seed in less than 1 year. Summer annuals germinate in the spring and mature in the fall. Winter annuals germinate in the fall or late winter and mature in the spring. Knowing this, you can see why timing of
mechanical removal and remediation is essential for eradication.
The University of Maryland Extension office has suggested the following cultural practices for a healthy turfgrass.
• Maintain proper soil pH – A soil test should be taken every 3 years to determine pH. Soil pH should be in the 6.0 to 6.8 range for optimal turf growth. Apply lime according to soil test results to achieve the desired pH.
• Fertilize at the proper time – Fall fertilization is recommended to encourage root development. If turf lacks dark green color and is weak and thin, a light late-spring application of fertilizer is also beneficial. Fertilizer should not be applied in the summer when turf is dormant and possibly under stress from hot, dry conditions. Do not bag grass clippings. Clippings that decompose on the lawn will not cause thatch to develop, but will recycle nutrients. Less fertilizer will need to be applied to your lawn.
• Irrigate only if necessary – Watering lawns is usually prohibited during a prolonged drought. Allow established tall fescue lawns to go dormant during hot, dry weather in the summer. The lawn will recover when rainfall and cooler temperatures return. Only newly seeded areas and lawns less than two years old should be irrigated.
• Mow at proper height – Close mowing weakens turf by removing too much leaf surface. Try to mow frequently enough that you remove no more than 1/3 of the blade at one mowing.
• Amend poor soil conditions by aerating compacted soil, adding organic matter to poor soil, and correcting drainage on poorly-drained sites. Aeration is best done in the fall. Spring is a wetter time and disturbing wet soil results in more compaction. Spring aeration opens up the soil for weed seeds to germinate.
• Use the proper seed for your site conditions – For sunny sites, plant turf-type tall fescue. In shade, plant fine fescue such as chewings fescue, creeping red fescue, or hard fescue.
• Buy quality seed – When buying seed, choose cultivars recommended by the Maryland-Virginia Turfgrass Variety Recommendation Work Group. Virginia and Maryland work together each spring evaluating which seed is the best for our area. http://www.pubs.ext.vt.edu/CSES/CSES-17/CSES-17.html. Check the grass seed label for the percentage of weed seeds. Percentage by weight of weed seeds should be less than 0.1%. Higher percentages indicate a poor quality grass seed. Avoid buying seed that contains any percentage of noxious weeds such as Cirsium arvense L. (Canada thistle), Poa annua L. (Annual bluegrass), or Dactyllis glomerata L (Orchardgrass.)
• Overseed to fill in thin or bare spots – Overseed in late August through early fall. The next best time is in early spring.
• Remove thatch – Thatch prevents water, air, and nutrients from reaching the soil. Thatch buildup tends to be more of a problem on Kentucky bluegrass and fine fescue lawns. If thatch is present, you will notice a brown layer of non-decomposed organic matter between the soil and the grass. If this layer is thicker than 1⁄2 inch, thatch removal is recommended. Thatch should be removed in the fall, while the turf is actively growing. Rent a vertical mower or core aerator for this task.
Identification of Weeds
I’ve been asked by many what spring weeds look like. For pictures of common spring weeds go to “Spring Weeds,” https://extension.umd.edu/hgic/weeds/spring-weeds.
Ready the Mower
Lastly, March is a perfect time to get your lawn mower ready for summer. Hopefully, it has been put away with the fuel emptied but if not….
- Remove the gasoline. Leftover gasoline from the previous year can become stale, choking the carburetor and causing rust.
- Disconnect the spark plug . This is if you decide to service the mower yourself. It disables the engine, making it safer to perform service on the machine.
- Remove the blade(s). While this piece is removed, sharpen it using a metal file. Sharpen them now, once in the summer and probably in the fall.
- Drain the oil. Four-cycle engines will need to be drained of oil and refilled with fresh oil
- Clean the equipment. Use a putty knife and wire brush to knock off accumulated grass and mud, then reattach the blade if you removed one earlier.
- Replace the air filter. This improves airflow to the engine, allowing it to run more smoothly.
- Replace the spark plug. Although your old spark plug may still work properly, installing a new one is a cheap and easy way to ensure optimal performance.
Most insects’ life cycles have not yet started in March, as the weather is still relatively unpredictable, and is often simply too cold for insects to survive. The vast majority of insect control tasks can wait until a bit later, until April and May.
- Perform a soil test and follow instructions for supplements such as lime.
- Correct drainage on poorly drained soil.
- Handpull winter annual weeds
- It is not necessary to fertilize established lawns in the spring
- Take your mower to the shop for servicing and blade sharpening or DIY
- It is too early to treat for damaging insects
Gussack, Eva and Rossi, Frank. Turfgrass Problems, Picture Clues and Management Options. Natural Resource, Agriculture and Engineering Services, June 2001.
“Spring Postemergent Lawn Weed Control,” Virginia Cooperative Extension Publication at http://www.ext.vt.edu/topics/lawn-garden/turfgrass/turfandgardentips/tips/spring-postemergent-Lawn-weed-cont.html (this is a podcast that you can listen to; you can also read the transcript)
“Soil Sampling for the Home Gardener,” Virginia Cooperative Extension Publication No. 452-129, http://pubs.ext.vt.edu/452-129/
“Establishing Lawns,” Virginia Cooperative Extension Publication No. 426-718, http://pubs.ext.vt.edu/426-718/
“Preemergent Hericides for Crabgrass Prevention in Lawns,” PlantTalk, University of Colorado State Cooperative Extension, http://www.ext.colostate.edu/ptlk/1541.html
“Weed control in lawns and other turf,” University of Minnesota Extension, http://www.extension.umn.edu/garden/yard-garden/lawns/weed-control-in-lawns/
“Spring Weeds,” University of Maryland Extension, Home and Garden Information Center, https://extension.umd.edu/hgic/weeds/spring-weeds
“Control Options: An Environmentally Responsible Approach to Weed Control,” University of Maryland Extension, https://extension.umd.edu/hgic/lawns/control-options
“Guide to Controlling Weeds in Cool Season Turf,” University of Maryland Extension, Home and Garden Information Center, Publication HG 101, http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG101%20Guide%20to%20Controlling%20Weeds%20in%20Cool%20Season%20Turf.pdf
“2014-2015 Virginia Turfgrass Variety Recommendations,” Virginia Cooperative Extension, http://www.pubs.ext.vt.edu/CSES/CSES-17/CSES-17.html